摘要
【目的】探究氮磷添加对全球生态脆弱区喀斯特草地土壤碳(C)、氮(N)、磷(P)化学计量特征的影响,为了解该区域草地对养分富集的响应提供理论依据。【方法】在贵州省2种喀斯特草地(围封草地和放牧草地)开展氮磷添加试验,设置4个处理,包括对照[CK,N 0 kg/(hm^(2)·yr)+P 0 kg/(hm^(2)·yr)]、氮添加[N,100 kg/(hm^(2)·yr)]、磷添加[P,100 kg/(hm^(2)·yr)]和氮磷共同添加[NP,N 100 kg/(hm^(2)·yr)+P 100 kg/(hm^(2)·yr)],研究喀斯特草地土壤碳(C)、氮(N)、磷(P)化学计量特征对氮磷输入的响应机制。【结果】N添加显著增加围封草地SOC(22.1%)和TN(30.0%)含量。P添加显著增加围封草地SOC(28.5%)、TN(35.6%)和2种草地TP含量(围封:84.7%,放牧:43.0%);显著降低C/P和N/P,对C/N无显著影响。NP添加显著增加放牧草地SOC含量(30.7%)及2种草地TN(围封:25.3%,放牧:21.4%)和TP(围封:65.6%,放牧:83.6%)含量,且显著降低2种草地C/P和N/P。此外,NP添加显著增加2种草地土壤AP含量。【结论】喀斯特草地对氮磷养分输入具有较强敏感性,短期内增加氮磷输入不仅增加土壤氮磷有效性,也改变喀斯特草地土壤C、N、P化学计量特征,且土壤C、N、P化学计量特征对P添加和NP添加的响应较N添加更敏感,尤其是围封草地。
[Objective]The impacts of nitrogen(N)and phosphorus(P)addition on soil carbon(C),nitrogen(N)and phosphorus(P)stoichiometric characteristics in karst grasslands,a globally ecologically fragile region were investigated to provide a theoretical basis for understanding grassland responses to nutrient enrichment in this area.[Method]A nutrient addition experiment was conducted in two karst grassland types(enclosed grassland and grazed grassland)in Guizhou province.Four treatments were applied,including control[CK,N O kg/(hm^(2)·yr)+P0 kg/(hm^(2)·yr)],N addition[N,100 kg/(hm^(2)·yr)],P addition[P,100 kg/(hm^(2)·yr)]and NP addition[NP,N 100 kg/(hm^(2)·yr)+P 100 kg/(hm^(2)·yr)].Soil C,N and P stoichiometric traits were analyzed to determine their responses to nutrient inputs.[Result]N addition significantly increased soil organic carbon(SOC)and total nitrogen(TN)in enclosed grasslands by 22.1%and 30.0%,respectively.P addition significantly elevated SOC(28.5%),TN(35.6%)and total phosphorus(TP)in both grasslands(enclosed:84.7%;grazed:43.0%).It also reduced C/P and N/P ratios but had no effect on C/N.NP addition markedly increased SOC(30.7%)in grazed grasslands and TN(enclosed:25.3%;grazed:21.4%)and TP(enclosed:65.6%;grazed:83.6%)in both grasslands.Additionally,C/P and N/P ratios decreased significantly in both grassland types,while available phosphorus(AP)increased.[Conclusion]Karst grasslands exhibit high sensitivity to N and P inputs.Short-term nutrient enrichment not only enhances soil N and P availability but also alters soil c,N and P stoichiometry.Responses to P addition and NP addition were more pronounced than to N addition,particularly in enclosed grasslands.
作者
杨富贵
李玉涛
叶靳
陈继辉
YANG Fu-gui;LI Yu-tao;YE Jin;CHEN Ji-hui(College of Animal Science of Guizhou University,Guiyang 550025,China)
出处
《西南农业学报》
北大核心
2025年第6期1297-1304,共8页
Southwest China Journal of Agricultural Sciences
基金
贵州省科学基金项目(黔科合基础-ZK[2022]一般040)
贵州省基础研究(自然科学)(黔科合基础MS[2025]584)
贵州大学后补助项目(贵大基础[2023]13号)。
关键词
喀斯特草地
氮磷添加
化学计量学
土壤养分
Karst grassland
Nitrogen and phosphorus addition
Stoichiometry
Soil nutrients
作者简介
第一作者:杨富贵(1999-),男,在读硕士,研究方向为草地养分管理。E-mail:19184695209@163.com;通信作者:陈继辉(1990-),男,博士,副教授,主要从事草地养分管理研究。E-mailjhchen3@gzu.edu.cn。
